The present invention relates to concrete screeds and, in particular, to extremely light weight, single operator, portable power vibratory "Wet Screeds" used to smooth and level freshly poured concrete without use of forms or other devices to ride or rest on, but rather floats on the concrete as it tamps and smooth the preparatory to final finishing.
To date, there exists no other prior art device which accomplishes these tasks simultaneously as does this invention.
Numerous screeds employ vibratory action to tamp and smooth the concrete in the final finishing step. U.S. Pat. No. 4,340,351 describes a vibratory concrete screed requiring two operators which is used in the final finishing of concrete. U.S. Pat. No. 4,641,995 describes a vibratory concrete screed which rides on forms to screed narrow strips of concrete such as walks. The screed in this patent is mounted on the operator via a complicated harness counter-weighted frame and is powered by electricity thus requiring the manipulation of lengthy extension cords and having electrical power on site.
Escalating labor costs and the unavailability of qualified concrete helpers has pushed the concrete finishers profitability margin down continually, thus forcing rising costs of construction nationwide. The current standard method of "Wet Screeding" freshly poured concrete is with a 2" by 4" board 8' to 12' long with one or two men bent over all day long, hand working the concrete as two to four laborers, "puddlers", push the fresh concrete, "mud", in place with concrete rakes. The hand process is not only slow, inefficient and labor intensive, it is also conducive to the addition of more water to the mix in order to make it more workable thus reducing the strength of the concrete, which can cause voids and weak spots. The addition of water to produce slumps of 6" to 8" so the finisher can effectively hand "Wet Screed" the fresh concrete is common in the industry nationwide today. The hand process limits the finisher to the average pour of 6,000 to a maximum of 8,000 square feet of slab per day for a crew of six.